Download The Sun

The Sun
By: Miss Kay
The Sun
• The Sun is the star at the center of our solar
system and is responsible for the Earth’s
climate and weather.
• The sun and its atmosphere are divided into
several zones and layers:
The solar interior, from the inside out, is made up of the core,
radiative zone and the convective zone. The solar atmosphere above
that consists of the photosphere, chromosphere, a transition region
and the corona.
Basic Facts
• Age: 4.6 Billion Years
Diameter: 1,392,684 km
Circumference at Equator: 4,370,005.6 km
Mass: 1,989,100,000,000,000,000,000 billion
kg (333,060 x Earth)
Surface Temperature: 5500 °C
The Structure
The Core
• Conditions at the Sun's core (approximately the
inner 25% of its radius) are extreme. The
temperature is 15.6 million Kelvin and the
pressure is 250 billion atmospheres. At the center
of the core the Sun's density is more than 150
times that of water.
• Although it only makes up roughly 2 percent of
the sun's volume, it is almost 15 times the density
of lead and holds nearly half of the sun's mass.
The Radiation Zone
• This zone extends from the core to 70 percent
of the way to the sun's surface, making up 32
percent of the sun's volume and 48 percent of
its mass. Light from the core gets scattered in
this zone, so that a single photon often may
take a million years to pass through.
The Convection Zone
• The convection zone reaches up to the sun's
surface, and makes up 66 percent of the sun's
volume but only a little more than 2 percent
of its mass. Roiling "convection cells" of gas
dominate this zone.
The Photosphere
• The photosphere is the lowest layer of the
sun's atmosphere, and emits the light we see.
It is about 300 miles (500 kilometers) thick,
although most of the light comes from its
lowest third. Temperatures there range from
11,000 degrees F (6,125 degrees C) at bottom
to 7,460 degrees F (4,125 degrees C) at top.
Sunspots
• Sunspots are "cool" regions, only 3800 K (they
look dark only by comparison with the
surrounding regions). Sunspots can be very
large, as much as 50,000 km in diameter.
Sunspots are caused by complicated and not
very well understood interactions with the
Sun's magnetic field.
The Chromosphere
• A small region known as the chromosphere
lies above the photosphere.
• This zone goes up to 35,500 degrees F (19,725
degrees C) and is apparently made up entirely
of spiky structures known as spicules typically
some 600 miles (1,000 kilometers) across and
up to 6,000 miles (10,000 kilometers) high.
The Transition Region
• This region is a few hundred to a few
thousand miles or kilometers thick, which is
heated by the corona above it and sheds most
of its light as ultraviolet rays
The Corona
• The highly rarefied region above the
chromosphere, called the corona, extends
millions of kilometers into space but is visible
only during a total solar eclipse.
• This region is made of structures such as loops
and streams of ionized gas. The corona generally
ranges from 900,000 degrees F (500,000 degrees
C) to 10.8 million degrees F (6 million degrees C)
and can even reach tens of millions of degrees
when a solar flare occurs. Matter from the corona
is blown off as the solar wind.
More Interesting Facts
• One million Earths could fit inside the Sun
• Eventually, the Sun will consume the Earth
• The Sun contains 99.86% of the mass in the Solar
System and is by far the largest object in the solar
system.
• The Sun is an almost perfect sphere
• Light from the Sun takes eight minutes to reach Earth
• The Sun travels at 220 kilometers per second
• The temperature inside the Sun can reach 15 million
degrees Celsius
References
• http://space-facts.com/the-sun/
• http://nineplanets.org/sol.html
• http://www.space.com/58-the-sun-formationfacts-and-characteristics.html